Improvement in spacing t-squares



J. D. DAY. Spacing T-Square.

No.199,192. Patented Jan. 15, 1878.

Jz/y% k A I A fi WITNESSES; J? u E on:

ATTORNEYS NPEIERS, PHOTO-UIHOGRAFHER, WASHINGTON D C UNITED STATES PATENT OFFICE.

JOSHUA D. DAY, OF NEW YORK, N. Y., ASSIGNOR TO HIMSELF, DANIEL T. AMES, OF SAME PLACE, AND CHARLES C. TAINTER, OF ELIZABETH,

IMPROVEMENT IN SPACING T- SQUARESQ Specification forming part of Letters Patent No. 199,192, dated January 15, 1873; application filed June 11, 1877.

To all whom it may concern Be it known that I, JOSHUA D. DAY, of New York, county of New York, and State of New York, have invented a new and Improved Spacing T-Square, of which the following is a specification:

Figure l is a plan or top view. Fig. 2 is a view of the under side. having a part broken away to show internal parts. Fig. 3 is a longitudinal section on line w x in Fig. 1. Fig. etis a transverse section on line y y in Fig. 1.

Similar letters of reference indicate corresponding parts.

My invention relates to T-squares used by draftsmen; and it consists in the arrangement of a fixed and a movable head, and an adj usting-screw for limiting the motion of the said movable head, and a graduated scale for indicating the distance between the lines to be made.

In the drawings, A is the blade of a T-square, to which is affixed the head B, in which is formed an undercut groove for the part 0 to slide in. The head B is rabbeted below the blade A, to form a shoulder for guiding the square along the edge of the draftingboard.

In the head B there is placed a screw, D, which is supported and guided by cars or standards athat project from the slotted plate 11 that is let into the face of the head B. A milled nut, E, is placed on the screw D between two of the cars a, and projects slightly through a slot in the plate b, so that it may be rotated easily by the finger or thumb.

An index, 0, is placed on the end of the screw D, and its end projects through a slot, (1, in the plate 12, and is traversed by a line that is brought opposite any graduation on the face of the plate I) that represents the space desired between the lines. A stud, 0, projects from the inner face of the movable part 0 of the head into the space between the end of the screw D and an ear, 2', formed on the plate I), for the purpose of limiting the motion of the movable part of the square.

By turning the milled nut E the screw D is moved in one direction or the other, to regulate the spaces set off by the squares.

It is obvious that the blade of the square may be either fixed or adjustable.

The manner of using my improved T-square is as follows: The headB and movable part 0 are placed against the edge of the draftingboard, and the head B is held lightly against the edge of the board, while the movable part 0 is carried forward. This part is then pressed against the edge of the board, while the head B is released and moved forward. These operations are carried on in alternation, and the lines are drawn at every step or at alternate steps taken by the square.

The plate b may he graduated to any convenient scale, or different scales may be provided at each side of the slot 01.

The working-faces of the parts B O are lined 

